Thanks, Anjana. What you're
describing sounds to me more like the evidence-based systematic reviews (EBSRs)
that we are definitely doing, an overview of the evidence in an
as-objective-as-possible, or at least transparent, way. I think the particulars
of the U.S. health care system, though, make the distinction between EBSRs
and guidelines a particularly important one for us.

Health insurors have latched on to the
whole idea of evidence-based medicine here, sometimes for the good, sometimes
not. In the latter case, insurors have issued there own (purportedly
evidence-based) practice guidelines which often are simply tools to deny
coverage. So, they will give their overview of the evidence and what they
consider that to mean in terms of best practice. On the patient care side, if we
"stop" at the overview of the evidence without taking the next step to say what
we think that means in terms of best practice, then we run the very real risk of
leaving theirs as the only voice to be heard describing best
practice.

So, as a researcher, I'm more than a little
uncomfortable with this excursion into the political sphere, but if I want my
work to have any impact...

-Rob

Rob Mullen

Director

National
Center for Evidence-Based Practice in
Communication Disorders

From: Evidence based health (EBH) on behalf of
Anjana N PatelSent: Sat 2/17/2007 7:25 AMTo:[log in to unmask]Subject: Re: What is "enough"
evidence to support a practice guideline?

Rob,

Perhaps you could look at this in a different way. A pragmatic
approach would be to aim to provide guidelines that are clearly
transparent about the 'state of the evidence' rather than determination of a
standard 'threshold' for sufficient evidence. Trying to determine a standard
'threshold' is difficult because the level of evidence varies for different
possible outcomes for the same intervention. A further complication is that
acceptability of risk also varies according to the possible outcomes i.e
'life or death' at one end of the spectrum and 'quality of life' at the other
end of the spectrum. There are people who would prefer to die rather than
live with a poor quality of life and other people who would choose to live at
any cost.

Another factor to bear in mind is the sole purpose of
'guidelines'. I view guidelines as resources to help health professionals make
difficult decisions (although some would argue that guidelines 'tell people what
to do' and 'Guidance' would be a more appropriate term to use). Guidelines are
misused for many reasons, but you cannot control how people use the guidelines
produced by your professional society.

In the world of pharmacy in the UK, guidelines are generally
considered to be useful if they are clear about:

1. the 'state of the evidence' from which a
recommendation was derived

2. when there is a situation where we just 'don't know', in
which case it is helpful to know what your colleagues would do when faced with a
similar situation (i.e. a consensus statement). Whether or not you choose to do
the same is entirely a personal decision but is necessary to be able to justify
it.

3. the 'life-span' of the guideline i.e. the date it was
first published and when it will be re-visited and updated if necessary. This
indicates a clear acknowledgement of the ever-changing nature of 'the evidence'
and clinical practice.

Our professional society is in the
process of moving from consensus-based clinical practice guidelines to
guidelines that are evidence-based. One aspect of this transition is that the
new guidelines (or updates of existing guidelines) will be preceded by and
directly linked to evidence-based systematic reviews.

One of the issues with which I’m
struggling is the determination of a “threshold” for sufficient evidence on
which to base a guideline. At one end of the spectrum is the position we could
take of issuing a guideline only when the evidence of what a clinician should
or should not do in a specific circumstance is so strong that to act
differently would be approaching malpractice. My concern here is that we would
issue very, very few guidelines, as we typically do not have that clarity of
evidence.

At the other end of the spectrum
is the position that we could issue a practice guideline any time there is a
preponderance of evidence in one direction or another, and qualify the
recommendations with caveats about the relative strength or weakness of the
supporting evidence, and the importance of incorporating clinical expertise
and patient values into the decision-making process. My concern is that the
caveats might often be ignored, and all of the guidance coming from my
organization would be considered on essentially equal
footing.

I’d appreciate any thoughts about
how to resolve this dilemma. Thank you!

-Rob

Rob Mullen

Director

National
Center for Evidence-Based Practice in
Communication Disorders